HPOP question/help

[SuperB]

Hey guys. I'm trying to find some information on how the high pressure oil pump system works.

I had the HPOP replace on my truck 6000 miles ago. It died on me while pulling a trailer. The truck would crank but not start.

So now I'm towing a trailer again and the truck starts making a knocking noise. It doesn't sound like a rod knock more like a really bad exhaust leak. But the knock is related to engine speed. It didn't really feel like it was losing power so I tried to go a little ways further. Then I had a big knock and the engine started smoking out of the air cleaner. I didn't notice any smoke from the exhaust (it was at night). So I had it towed to a shop and the mechanic said he thought it was something fuel related or something with the high pressure oil line, but he wasn't equipped to fix it there. So I had it towed to my local ford dealer and they said their computer says low oil pressure caused from a bad HPOP and they also said something about cyls 5&6 having 15% lower compression than the others. They want ~$600 to remove the valve covers, do a compression check and manually check the pressure output from the HPOP. Does this sound right? What would cause the HPOP to go out so soon? When it was replaced I had the IPR valve done also. I'm just trying to understand this so I don't get taken advantage of?

Any help is greatly appreciated.

 

[rdytow]

I had a HPOP replaced at my local dealer, and, when it went out later, at about 7,500 miles, it was covered under warranty. Have you checked to see if you have a warranty on the HPOP if the dealer replaced it originally?

 

[hulkster]

OK.
If you had the hpop replaced at a Ford dealer it has a 12 month 12 thousand mile warranty.
You do not have to pull valve covers to do a manual compression test on a 6.0or a 6.4
If you do not have base oil pressure your not going to have High Oil Prssure. Basically the hpop ramps up base oil pressure to drive the injectors,minimum of 500 psi when you crank the engine 499.9 psi or less,truck will not start. 15% low on a compression reading is not good, so yes, a manual compression test has to be done, then valve covers off to look for bent pushrod,broken valve spring etc. I have never seen a hpop failure cause engine knock or compression problems, in fact it's almost impossible.. Give them the 600 to check it out properly,at least you will know.